Bacteriological transfer loops



p 1, 1964 J. .1. CONNORS 3,147,197

BACTERIOLOGICAL TRANSFER LOOPS Filed July 22. 1960 FIG. 2.

INVENTOR.

Joseph J. Connors BY L.

United States Patent 3,147,197 BACTERIULOGICAL TRANSFER LOQPS Joseph J. Connors, Contra Costa County, Calif. (654- Beloit Ave, Berkeley 8, Calif.) Filed July 22, 1960, Ser. No. 44,755 1 Claim. (Cl. 195-127) This invention comprises an improvement in bacteriological transfer loops which permits multiple, pre-sterilized, transfer loops to be employed in effecting transfers from one bacteriological medium to another.

The transfer of liquid medium containing, or suspected of containing, bacteria from one culture medium to another is a common requirement in the practice of the science of bacteriology. Such transfers are usually accomplished by the use of a wire bent into a closed circular loop at one end, and held at the other end by a heat-insulating handle. Such wire loops, called transfer or inoculating loops, are commonly made of platinum or other inert material and must be sterilized by heating to redheat, then usually cooled, before each individual transfer.

The amount of liquid transferred by such transfer loops is not critical, the minimum being established by the successful employment for more than sixty years by competent practitioners of the science of bacteriology of wire loops not less than three millimeters in diameter, and the maximum amount of liquid transferred being limited only by the consideration that the receiving liquid not have its chemical constitution significantly changed by the addition of the inoculum.

The necessity to reduce the time required to sterilize transfer loops dictates their fabrication from thin and consequently easily deformed Wire. Considerable training, practice, and care are required to avoid deformation of these wire transfer loops, either in use or in storage.

In the daily practice of the science of bacteriology in all its phases, but particularly in that branch known as water bacteriology, numerous transfers must be made, and much time is spent in the subsidiary process of heatsterilizing the transfer loop before a transfer can be made.

The present invention comprises transfer loops that are non-deforming in ordinary use, capable of being presterilized, and that meet the accepted requirements for volume of inoculum transferred.

It is therefore an object of the invention to provide presterilizable loops that are used to eifect one transfer per loop.

It is a further object of the invention to provide transfer loops that are non-deforming in ordinary use and from a group of which a single loop can be selected without contamination or undue disturbance of the remaining loops.

A still further object of the invention is to provide transfer loops that can be re-used indefinitely after appropriate sterilization,

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The invention will best be understood by reference to the following specification of the preferred embodiment, taken in conjunction with the accompanying drawing to which reference will be made.

In its preferred embodiment, the invention consists of a strip of metal, such as stainless steel, inert to the bacteriological medium in which it is to be employed. Referring to FIGURE 1, the strip has a hole not less than three millimeters in diameter at one end, and this hole is surrounded by approximately one millimeter of metal on the side away from the shank 11. The portion of the shank 12, adjacent to the hole, is reduced in area so as to produce the minimum surface that can be wetted while still retaining sufiicient strength and rigidity. The shank 11 is bent along its long central axis to form an interior angle of less than degrees, strengthening the strip and permitting the use of thin metal. FIGURE 2 shows a typical cross-section 2-2 of the shank 11.

In other embodiments the circular opening in the loop may be replaced by openings of other shapes, such as ovals, or slots open at the end away from the shank 11. In such cases the area of the film of liquid formed over the opening must be at least equal to that formed over a circular opening not less than three millimeters in diameter.

Having described the invention What is claimed as new A bacteriological transfer loop device comprising, an elongated one piece strip of sheet metal perforated at one end to provide an opening and surrounding relatively narrow wall defining a rigid liquid transfer loop, said strip providing an integral elongated straight handle portion extending from said wall and being joined thereto in a tapered shank portion, said handle portion being formed of a width and thickness and with a longitudinally extending open valley extending over a major portion of its length affording rigidity in use and functioning to assist in lining up a plurality of said devices in parallel position when mounted together in a container.

References Cited in the file of this patent UNITED STATES PATENTS D. 186,157 Whamond Sept. 22, 1959 2,245,067 Brown June 10, 1941 2,836,926 Tseng June 3, 1958 OTHER REFERENCES Surgical Instruments of Superior Quality, The Kny- Scheerer Co., New York, N.Y., page 3002 (1915). (Available in Design DivisionRD76. K58 1915a Design.)

Aloe Lab. Appts. Equip Reagents Catalogue 103 (1952), pp. 710 and 711. Copy in Library. 

